Page "Declarative memory" Paragraph 34

Slow-Wave Sleep, often referred to as deep sleep, plays the most important role in consolidation of declarative memory and there is a large amount of evidence to support this claim.

One study found that the first 3. 5 hours of sleep offer the greatest performance enhancement on memory recall tasks because the first couple of hours are dominated by SWS.

Additional hours of sleep do not add to the initial level of performance.

Thus this study suggests that full sleep may not be important for optimal performance of memory.

Another study shows that people who experience SWS during the first half of their sleep cycle compared to subjects who did not, showed better recall of information.

However this is not the case for subjects who were tested for the second half of their sleep cycle, as they experience less SWS.